Insertion of CO₂ and CS₂ into Bi-N bonds enables catalyzed CH-activation and light-induced bismuthinidene transfer

The uptake and release of small molecules continue to be challenging tasks of utmost importance in synthetic chemistry. The combination of such small molecule activation with subsequent transformations to generate unusual reactivity patterns opens up new prospects for this field of research. Here, we report the reaction of CO₂ and CS₂ with cationic bismuth(iii) amides. CO₂-uptake gives isolable, but metastable compounds, which upon release of CO₂ undergo CH activation. These transformations could be transferred to the catalytic regime, which formally corresponds to a CO₂-catalyzed CH activation. The CS₂-insertion products are thermally stable, but undergo a highly selective reductive elimination under photochemical conditions to give benzothiazolethiones. The low-valent inorganic product of this reaction, Bi(i)OTf, could be trapped, showcasing the first example of light-induced bismuthinidene transfer.